Field
This disclosure relates generally to semiconductor device packaging, and more specifically, to quad flat no lead packages stacked with other packaged semiconductor devices.
Related Art
Lead frames provide a central supporting structure of molded IC packages to which all other elements of the molded IC package are attached. Lead frames are etched or stamped from a thin sheet metal strip to form a pattern of terminals around a central die attach platform upon which a die is mounted using, for example, an epoxy resin. The die includes bonding pads which are electrically connected to the surrounding lead terminals of the frame by fine-diameter conductive wires using well-established wire bond techniques. The assembly including the lead frame, die, and wires are covered with a thermoset plastic casing to complete the molded IC package.
Array quad flat no lead (QFN) and power QFN (PQFN) packages typically comprise an integrated circuit (IC) die attached and electrically connected to a lead frame with more than one rows of lead terminal. The IC die, the electrical connections and a portion of the lead frame are encapsulated by a mold compound, leaving a portion of the leads exposed. The exposed leads serve as input and output (IO) connections to the encapsulated IC die and are typically located along a periphery of the QFN package. Because QFN packages provide a number of advantages over other lead frame package configurations including, for example, shorter electrical paths and faster signal communication rates, QFN packages are widely used as low pin count solutions for power elements and other IC die.